prototype

A UI prototyping skill that creates several substantially different versions of a described interface component and shows them in a live picker.

In plain words
What is it for?
Use it to explore alternatives for elements such as toasts, pricing cards, or confirmation buttons, including their motion and reduced-motion behavior.
Why use it?
It makes design choices easier to compare by letting you see and choose among distinct working directions instead of discussing one version at a time.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/stvlynn/dsh.fish/prototype
Any agent
npx skills add stvlynn/dsh.fish --skill prototype
Clone the repo
git clone --depth 1 https://github.com/stvlynn/dsh.fish

Made for: Claude Code, Codex.

Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,634 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00048 $0.01634
Opus 5 $0.00024 $0.00817
Sonnet 5 $0.00010 $0.00327
Haiku 4.5 $0.00005 $0.00163

Measured 2d ago against content hash 2ad8401c4dea, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

prototype scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to prototype — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/skills/prototype/SKILL.md · 91 lines

How it starts

The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prototyping Variants

A divergence skill. It does ONE thing: take a described piece of UI ("a toast", "the pricing card", "a hold-to-delete button"), build several genuinely different versions of it, and put them behind a visual picker so the user can flip through them live and choose a winner. It does not review existing UI (that's review-animations), plan fixes for it (that's improve-animations), or choose dependencies (that's pick-ui-library).

Operating Posture

You are a senior design engineer running a design exploration. The entire value of this skill is divergence: three tints of the same idea waste the picker — the user learns nothing by flipping between them. Each variant must be a direction you could defend shipping on its own, exploring a genuinely different answer to the same brief.

Divergence is not an excuse to drop the craft bar. Every variant individually meets Emil Kowalski's standards — right easing (ease-out on entrances, never ease-in), sub-300ms UI motion, correct transform-origin, transform/opacity only, reduced-motion handled. A sloppy variant doesn't widen the exploration; it just loses on execution and teaches nothing about the direction it represents.

Hard Rules

  1. Never touch production code during exploration. Everything lives in an isolated prototype surface (see Phase 4). Integration happens only in Phase 6, only for the variant the user picked.
  2. Variants diverge on a named axis — layout, density, personality, motion, interaction model. Before building, you must be able to state each variant's axis in a phrase. Sharing the project's tokens is not convergence; variants should feel native to the product.
  3. Every variant fully works. Real interactions, real motion, realistic content — actual product-shaped copy, plausible names and numbers. No lorem ipsum, no dead buttons, no "imagine this part".
  4. The picker is chrome, not a contestant. Its exact markup, styles, and behavior are specified in PICKER.md — copy them verbatim. Its look is not a design decision and never adapts to the project.
  5. Clean up after the choice. When a winner is promoted, delete the prototype surface unless the user asks to keep it.

Read the full file on GitHub · 91 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 91 lines · 48 tokens per session scan A 2ad8401c4dea

Subscribe to this mod's changes

prototype is a skill published in the GitHub repository stvlynn/dsh.fish (2 stars, last pushed 3d ago), licensed MIT. It adds 48 tokens to every session and 1,634 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to prototype, differing in 0 lines, and is treated as a copy.